ROYGBIV

ROYGBIV is an acronym for the sequence of colors commonly depicted in the visible light spectrum: red, orange, yellow, green, blue, indigo, violet. The order from long to short wavelength begins with red and ends with violet, though the boundary between blue, indigo, and violet is not sharply defined in practice.

Historically, Isaac Newton demonstrated the visible spectrum using a prism and identified seven distinct colors, a convention that influenced later teaching. In many modern educational contexts, indigo is treated as a shade of blue or violet, and the mnemonic is often rendered as ROY G. BIV. Variants include “Richard Of York Gave Battle In Vain” or “Red Orange Yellow Green Blue Indigo Violet.”

Conceptually, the colors arise from wavelengths roughly spanning red ~620-750 nm to violet ~380-450 nm, with approximate boundaries. The human eye perceives color via cone cells sensitive to different wavelengths, and color classification is a perceptual construct rather than discrete wavelengths.

Beyond optics, ROYGBIV is used in art, design, and printing to aid color recall and to illustrate the spectrum. It is also related to color models and color spaces that map perceptual color to numerical coordinates, such as RGB for light and CMYK for pigments.